Signaling system



Aug. 10, 1943. l.. L. EAGoN ETAL SIGNALING SYSTEM Filed Apri; 22, 1941 VHI'H" n @l1 h h u S DME@ D N n a Q v .hv n vf r N w Q L P h U [Q Wm m ATTORNE V Patented Aug. 10, 1943 lt.szrasfiais Y t YsioiyAI.INo sYsfraM I Laye Ll negen, New York, N.'Y anaurtc n McKinL-,East Orange, N. J., assignors Vto BellY Telephone Laboratories,` Incorporated, New

York, N. Y., a corporation of New Yorkv application April 22, 1941, semi Nc. 339,706: 'I

`3 claires.' (ci. 17e-5s) This invention relates to telephone exchange systems and more particularly to Signaling systems in which calling lines cause one or more so calledline lamps to be lighted before an operator.

A11 object of the invention-is to indicate to the operator the seniority of waiting calls by iiashing been waiting the longest time.

A feature of the invention resides in a. .so-called electrical gate which permits all waitingv lines,

the line lamps of those calling lines which have indicated by steadily lighted Vline lamps, to ad- Vance within the gate when it is vopened by answering all lines already within thev gate where# upon thesteadily lighted line lamps of the lines so admitted start to ia'shancl-the gate is closed to subsequently calling lines untilv the lines 'now Within the gate are allanswered vat which vtime the gate is againv openedA to admit the next group of calling lines to'repeat the cycle.

The invention will Vbe understood from the following description when read in connection with Simultaneously'f with the closure of contacts I9 of relay IB, 'contacts 2l areclosed thereby causing vsluggish relay I8 to operate. AWhen relay I3 fully operates it opens its right Vcontacts therebylre'- moving vground from conductor Il and at-its left contactsconnects interrupted ground, under con@ the accompanying drawing which shows three lines terminating at a telephone switchboard whose line lamp circuits are arranged in accordance with said invention.

Referring to the drawing, `a relay such 'as I, associated with line circuit L1, is operated when a call arrives and is released when the operator inserts plug 2 in jack 3 to answer the call which will be obvious, i. e., the insertion of the plug closes a circuit for sleeve relay 4 which operates thereby operating relay 5 to open the energizing circuit for relay I. Operation of relay I closes a circuit to light line lamp 6 which can be traced from battery, contacts of relay I, conductor l1, contacts 8 and 9, in parallel, of relays I!) and II,

respectively, conductor |21 and winding of relay I3 to ground which latter relay energizes lamp 6,'

and all others which may be connected in multiple therewith at other switchboard p-ositions.

In case no prior calling lines yare Waiting, *the Y loperation of relay I3 will also complete a circuit of relay I8. Relay IIJ operates in .this circuit and locks at its contact I 9 to battery on conductor 'I1 from relay I. Immediately thereafter contacts 8 are opened, thereby opening one of the parallel paths for relay I3, followed by closure of Contact` 20 and the subsequent opening of contact I6. Closure ofV contacts 2li completes a 'second holding circuit for relay ID for a purpose hereinafter referred to.

trol Vof interruptor I, to alternately operate and release relay II. .When relay IIOperatea-itopens its contacts 9 thereby 4releasing lrelay VMito-.extinguish lamp 6. The releaseofrelayIS also opens its contacts I4which breaksonepf the lockingV circuits of relay'lll. This relay, however, is hel'd byitsyleft winding. g 'n Y When interruptor I removes ground from relay I I, this relay is released thereby reclosing its contactsS and reoperating relay I3 which relights lamp 6 andatthe same timerecloses the second locking circuit for relay I!) which includes the right winding of that relay.A 1

Under control of interrupter I, relay II alter-Y nately operates and releases thereby flashing lamp 6 at the rate determined by the speed of the interrupter which in practice may be of the order of 120 times a minute.

Now let it be assumed that before the operator 1 answers the call on line L1, calls are initiated onl lines L2 and L3, the line circuits of which are ident tical with the circuit of L1 but are not shown in cause operation of a relay, corresponding to relay vremoving ground `from conductor Il.

1 manner a call on line L2 causes battery to be con'- nected to conductor 'I3 which is Vextended 'over conductor |23 to light the Vlinelamp 24 andto v cause battery to be connected to conductor I 5ar I3, and the consequent lighting of line lamp 22 and the connection of battery to conductor |52,

which, however, is ineffective to operate relay 23.

due to the fact that relay I8 is operated thereby In like which,v as in the case of line L2, is ineffective to operate relay 25 due to the absence of ground on conductor I1. Line lamps 22 and 24, therefore, remain steadily lighted as long as line L1 remains unanswered, as indicated by the flashing of lamp 6.

When the operator inserts plug 2 in lack 3 to answer the call on line L1, sleeve relay 4 operates from batteryl on the sleeve of plug 2 which causes operation `ofrelay 5. Relay 5 opens the energizing circuit for relay I which thereupon releases to remove battery from conductor 11,

thereby opening the holding circuit for relay I0,

which includesits'left winding, and causes the immediate release of relay I3 and the consequent extinguishing of lamp `Iz. When relay I3 releases the second holding circuit for relay I0, which is through its right Winding, is opened and this re- Y lay then releases thereby opening, at its contacts 2I, the energizing circuit of sluggish relay I8 which releases slowly. I The release of relay I8 disconnects interrupter I from relayV Il and reconnects ground to conductor II.

It will be noted as previously described, that calls are now waiting on lines L2 and L3 asindicated by the steady illumination ofline lamps 22 and 24 but that up to this time relays 2 3 and 25 have not operated due Vtothe absence. of ground on conductor I1. At this time, however, when ground is reconnected to conductor I'I, by the release ofrelay I8, both of these relays, 23 and 25, operate due to current flowing in their right windings thereby connecting ground at their right contacts to reoperate relay I8 whereupon interrupter I is again connected to relay I I, which relay changes lamps 22 and v24 from'steady to flashing.

Relaysr 23 and 25 also lock 'upto batteryV on conductors 12 'and 1a, respectivelyand the' reoperation of relay I8 again removes ground from conductor IIthus preventing any subsequently calling 1ine,"such as line L1, from operating 'its respective gate relay, such as ID," and consequently, the line lamps of Ysuch subsequently callmg une win mereiynght and remain lighted until the lines Lz and La, Whoselamps are now flashing,

areanswered. When both these lines,however,Y

What is claimed is: l. In a telephone system comprising a switch- Vboard terminating a group of lines having individual signals, and having means for answering calling ones of said lines, in which a call on any line causes the energization of its respective signals'and the answeringfof a call causes retirement Vof the signals, characterized -by means whereby the signals of a ilrst Calling line are intermittently deenergized until retired, and the signals of all subsequent calling lines are steadily energized until the rst calling line signals are retired, whereupon all steadily energized signals are intermittently deenergized until their retirement and the signals of all lines calling subsequent thereto are'steadily energized until the signals being vintermittently controlled are all retired. Y

Y 2V. In a telephone exchange system, an operators position, a plurality of lines terminating at said position, a kcall signal individual to `each line, a rstmeans Vassociated with each line responsive to a call thereover to energize ,the respective linersignahand a second means individual to each line, "operated in response toactuation of the respective-mstmean's,rto cause intermittent deenergization of the respective line signal and to disable thesecond means associated with all remaining non-calling lines.`

3. In a telephone exchange system, a switchboard, lines having call signals terminating thereat, means responsive to the rst line calling to causev the respective'signal to flash-until the call vvis answered, to cause all subsequent calling line signals to -be steadily displayed until the line of the flashing signal is answered and to thereafter cause all steadilydisplayed signals to llas until their respective lines-'are answered. H

. LLOYD L. EAGON.

BURTON McKIM. 

